Description (taken directly from the application): The overall goal of this Core Laboratory is to provide investigators in the individual Scientific Projects access to reliable and reproducibly maintained whole animal and cellular models for the study of basic molecular mechanisms of insulin secretion and its alterations in diabetes and the regulation of programmed cell death by intracellular Ca2+. The services provided by this Core Laboratory will be utilized by all three Scientific Projects. The Specific Aims are: 1. To - 22 -provide investigators access to specially defined animal models of beta-cell dysfunction and spontaneous diabetes and the appropriate non-diabetic control animals. These models include the NOD mouse, a model of autoimmune beta-cell destruction, the NOD mouse in which diabetes has been prevented by immunotherapy and the NOD scid/scid mouse in which diabetes has been adoptively transferred using spleen cells from diabetic NOD mice. The ZDF rat and the db/db mouse, models of spontaneous diabetes and reduced beta-cell mass will also be made available. 2. To isolate islets and prepare dispersed islet cells from the animal models of beta-cell dysfunction listed above and from normal rats and mice. 3. To maintain in culture, beta-cell tumor lines including betaTC3, MIN-6, HIT-T15 and RINm5F cells and other cell lines used to express beta-cell specific genes, related gene isoforms and stably transfected cell lines (e.g., COS-7 cells). 4. To perform perifusion experiments to study the regulation of insulin secretion in islets from normal or diabetic rodents or from beta-cell lines maintained in tissue culture. 5. To perform perifusion experiments to study the regulation of beta-cell intracellular Ca2+ in islets and cell lines maintained in tissue culture.